When a researcher finds an interesting topic to study such as aggression, the goal is often to study it in a way that is as true to life as possible. However, researchers must act in an ethical manner. To do this, they must balance their research goals with the best interests of the participants. Ethics often enter into the planning process when researchers identify all of the ways they can manipulate or measure a variable, but then make their final decision based on how they should manipulate or measure a variable.
After receiving a poor grade on a test or paper, a college student may appear to take it out on (i.e., act in an aggressive manner toward) their roommates by being mean or nasty, screaming, throwing things, or even becoming physically violent. Aggression is an important human behavior to study and understand due to the implications it has for interpersonal violence. However, for safety reasons, a study cannot expose participants to the risk that serious types of violence presents. As a result, researchers must identify similar but benign behaviors that can help us understand more aggressive behaviors without harming participants.

As an Assistant Professor of Psychology and Cognitive Science at Johns Hopkins University, I teach Introduction to Cognitive Psychology. This large class primarily consists of freshman and sophomores majoring in related fields, like Psychology, Neuroscience, or Cognitive Science. One of the challenges I face in the classroom is teaching students to appreciate how data are obtained in the process of performing experiments. Students have difficulty in appreciating the chronology of experiments as they unfold in time.
This JoVE collection in Cognitive Psychology makes the experimental timeline absolutely clear and encourages students to understand the trajectory and not just jump to conclusions. The videos also present experiments as paradigms—to illustrate how researchers can implement tasks in different ways—depending on the questions at hand. Most of these questions translate to the real world and the limits of our cognition. For example, the video Measuring Verbal Working Memory Span demonstrates our limited memory capacity, which explains the difficulty in remembering long shopping lists.
These JoVE videos in Cognitive Psychology provide a perfect place fo…

As the Department Chair of Psychology at Monmouth University, I teach primarily upper level undergraduate students who are interested in Experimental Methods. These classes don’t have the same inherent appeal to students. This JoVE Psychology collection will help students vicariously watch the experiments being performed from start to finish, allowing them to gain exposure to over a dozen topics that they may not experience otherwise. Importantly, the videos provide a context for seeing the experiments embedded in their natural states—in the actual research process.
A few projects in this Science Education collection stand out. First, I consider the Ethics in Psychological Research video to be very useful in teaching, as it demonstrates how sensitive topics, such as interpersonal violence, can be studied in creative ways. Furthermore, students learn better with topics that they care about and can conceptualize in their personal lives. For example, Observational Research delves into the factors that go into homesickness, going beyond questionnaires and examining the relationship to what individuals actually leave around in their rooms. This design al…

In order to study something scientifically, a researcher needs to determine a way to quantify it. However, psychological constructs can be challenging to measure and quantify. This video examines reliability in the context of content analysis.
A recent study in the journal Pediatrics reported that 4-year-olds who watched a fast-paced cartoon had worse performance on cognitive tasks, such as following rules in a game, listening to direction from an adult, and delaying gratification, compared to other children who watched a slower paced cartoon.1 In addition to the pace of the cartoon, the content of the cartoon may also have deleterious effects on its young viewers.
This video uses a simple two-group design, to exemplify the issue of reliability, in examining the question of whether the cartoon SpongeBob SquarePants has more inappropriate content than does the cartoon Caillou.…

The distractor-response binding paradigm is described. It can be used to shed light on the influence irrelevant stimuli, competing with targets for a response, can have on human action. Both response retrieval effects and distractor inhibition effects can be analyzed within the paradigm.

1Department of Psychology, University of New Mexico, 2Department of Neurology, University of California, San Francisco, 3Department of Physiology, Center for Integrative Neuroscience, University of California, San Francisco, 4Department of Psychiatry, University of California, San Francisco

A novel cognitive paradigm is developed to elucidate behavioral and neural correlates of interference by to-be-ignored distractors versus interference by to-be-attended interruptors during a working memory task. In this manuscript, several variants of this paradigm are detailed, and data obtained with this paradigm in younger/older adult participants is reviewed.…

We aim to identify the neural correlates underlying sustained and transient thought suppression, and thought re-emergence in controls, at-risk and depressed individuals. Activation was greatest for controls compared to the at-risk and the depressed group in the dorsolateral prefrontal cortex during thought suppression and anterior cingulate cortex during thought re-emergence.…

Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science. …

Investigation of the Uncanny Valley Hypothesis and affective experience requires an understanding of the hypothesis' dimension of human likeness (DHL). This protocol allows representation of the DHL and examination of categorical perception. Use of the same stimuli and fMRI to distinguish brain regions responsive to physical and category change is illustrated.…

The ambition of experimental psychology is to characterize the mental events that support the human ability to solve problems, perceive the world, and turn thoughts into words and sentences. But people cannot see or feel those mental events; they cannot be weighed, combined in test tubes, or grown in a dish. Wanting to study mental life, nonetheless, Franciscus Donders, a Dutch ophthalmologist in the early 1800s, came up with a property that he could measure—even back then: he measured the time it took for human subjects to perform simple tasks, reasoning that he could treat those measurements as proxies for the time it takes to complete the unobservable mental operations involved. In fact, Donders went one step further, developing a basic experimental paradigm known as the Method of Subtraction. It simply asks a researcher to design two tasks that are identical in nearly every way, excepting a mental operation hypothesized to be involved in one of the tasks and omitted in the other. The researcher then measures the time it takes to complete each task, and by subtracting the outcomes, he extracts an estimate of the time it takes to execute the one mental operation of interest. In this way, the method allows a researcher …

The Proboscis Extension Response (PER) conditioning protocol, developed for the honey bee (Apis mellifera), provides an ecologically-relevant and easily quantifiable means for studying several different mechanisms of learning in many insect species.

1Movement to Health Laboratory (EuroMov), University of Montpellier, 2Institut Universitaire de France, 3Department of Cognitive Psychology, University of Finance and Management in Warsaw, 4International Laboratory for Brain, Music, and Sound Research (BRAMS)

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

This article describes how to record amygdala activity with magnetoencephalography (MEG). In addition this article will describe how to conduct trace fear conditioning without awareness, a task that activates the amygdala. It will cover 3 topics: 1) Designing a trace conditioning paradigm using backward masking to manipulate awareness. 2) Recording brain activity during the task using magnetoencephalography. 3) Using source imaging to recover signal from subcortical structures.…

Research on social exclusion has grown tremendously in recent years. As the field expands, it is imperative to develop sophisticated methodologies allowing for the simultaneous measurement of neural and behavioral outcomes during social exclusion. This protocol utilizes event-related brain potentials to record ongoing neural activity during computerized social interactions. …

We present a protocol used to discover an interactive effect between sleep and cortisol on memory consolidation, particularly for negative arousing images. Specifically, the experimental design utilizes eye tracking, salivary cortisol analysis, and behavioral memory testing – methods that can be used with both healthy and clinical participants.

The present article describes how to use eye tracking methodologies to study the cognitive processes involved in text comprehension. Descriptions of eye tracking equipment, how to develop experimental stimuli, and procedural recommendations are included. The information presented can be applied to most any study using verbal stimuli.

Conditioned fear can be diminished through an inhibitory process called extinction, but can resurface under conditions such as the passage of time or exposure to stress. Our protocol presents a novel way of preventing fear recovery by introducing extinction during the reconsolidation window (the re-storage phase of a reactivated memory).

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

Fully automated system for measuring physiologically meaningful properties of the mechanisms mediating spatial localization, temporal localization, duration, rate and probability estimation, risk assessment, impulsivity, and the accuracy and precision of memory, in order to assess the effects of genetic and pharmacological manipulations on foundational mechanisms of cognition in mice.…

The ability to assess executive functions such as behavioral flexibility in rats is useful for investigating the neurobiology of cognition in both intact animals and disease models. Here we describe automated tasks for assessing strategy shifting and reversal learning, which are particularly sensitive to disruptions in prefrontal cortical networks.

Research studies come into being when a researcher speculates about human thought, emotions, or behavior, and has a theory that offers a potential explanation. Often the researcher’s theory is firmly situated in everyday common experiences that may not naturally lend themselves to direct empirical study.
For example, researchers speculated that perception of a person on Facebook is influenced by the appearances and comments of the person’s Facebook friends.1 It is difficult to test this theory using real-life Facebook profiles. Instead, researchers must use their creativity to design a study—in this case, using fake profiles that look highly realistic—to test their theory.
This video demonstrates how researchers test a central tenet of a popular social psychology theory. Specifically, this video shows a test of whether engaging in a self-expanding activity leads a person to feel a greater sense of self-efficacy.2
Psychological studies often use higher sample sizes than studies in other sciences. A large number …

Using event-related EEG potentials (ERPs), we investigate the effects of antipsychotic medications on abnormal semantic brain activations in healthy individuals with schizotypal traits. We use ERPs to track distinct changes in brain activity, shedding insight into the cognitive processes associated with semantic categorization.

A factorial design is a common type of experiment where there are two or more independent variables. This video demonstrates a 2 x 2 factorial design used to explore how self-awareness and self-esteem may influence the ability to decipher nonverbal signals. This video leads students through the basics of a factorial design including, the nature of a factorial design and what distinguishes it from other designs, the benefits of factorial design, the importance and nature of interactions, main effect and interaction hypotheses, and how to conduct a factorial experiment.…

1Center for Population and Development Studies, Harvard School of Public Health, 2Department of Medicine, Brigham and Women's Hospital, 3Division of Sleep Medicine, Harvard Medical School, 4Department of Biobehavioral Health, Pennsylvania State University

Biomarkers are directly-measured biological indicators of disease or health. In population and social sciences, biomarkers need to be easy to obtain, transport, and analyze. Dried Blood Spot (DBS) collection meets this need, can be collected in the field with high response rates and analyzed for a variety of biomarkers.

1Center for Visual Science, University of Rochester, 2Faculty of Psychology and Educational Sciences, University of Geneva, 3Department of Psychology, University of Wisconsin-Madison, 4Department of Brain and Cognitive Sciences, University of Rochester

To replicate laboratory settings, online data collection methods for visual tasks require tight control over stimulus presentation. We outline methods for the use of a web application to collect performance data on two tests of visual attention.

Reading in color is a new method for training letter-color associations that are typically found only in grapheme-color synesthetes. It involves an implicit form of training that has potential for long-term associative training methods because the training is a byproduct of reading and any text can be colored.

Here we describe a data collection and data analysis method for functional Near Infrared Spectroscopy (fNIRS), a novel non-invasive brain imaging system used in cognitive neuroscience, particularly in studying child brain development. This method provides a universal standard of data acquisition and analysis vital to data interpretation and scientific discovery.

One of the challenges in measuring an experimental variable is identifying the technique that will produce the more accurate measurement. The most common way to measure a dependent variable is self-report—asking the participant to describe his/her feelings, thoughts, or behaviors. Yet, people may not be honest. To truly know something about a participant, it may be necessary to see what they actually do in a situation.
This video uses a multi-group experiment to see if feeling close to others results in more favorable attitudes toward environmental consciousness measured both by self-report and behavioral observation.
Psychological studies often use higher sample sizes than studies in other sciences. A large number of participants helps to better ensure that the population under study is better represented, i.e., the margin of error accompanied by studying human behavior is sufficiently accounted for. In this video, we demonstrate this experiment using just one participant. However, as represented in the results, we used a total of 186 participants to reach the experiment’s conclusions.…

A reliable home-based way to assess the language comprehension of very young typically developing children, as well as those with autism, is described. The method analyzes children's eye gaze while viewing side-by-side images but hearing an audio that matches only one image. Stimuli are designed with young participants in mind.

Here we describe a touch-screen visual search paradigm that can be used to study threat detection across the lifespan. The paradigm has already been used in various studies demonstrating that both children and adults detect threatening stimuli like snakes, spiders, and angry faces faster than non-threatening stimuli.

When orchestrating an experiment, it is important that the experience elicits the most natural reactions from the participants as possible. Researchers accomplish much of this through their creation of the experimental settings.
Many research projects focus on interactions between two or more people. In these situations the environment or setting must often be less natural; often only one person can be a true participant and others in the study need to be “confederates,” that is, allegedly unbiased participants whom, in actuality, act according to the researcher’s directions.
This video uses a two-group experiment to see if participants are more likely to imitate a person with more power versus similar power compared to the participant. The video also highlights the use of research confederates.
Psychological studies often use higher sample sizes than studies in other sciences. A large number of participants helps to better ensure that the population under study is better represented, i.e. the margin of error accompanied by studying human behavior is sufficiently accou…

Binocular rivalry occurs when the eyes are presented with different images at the same location: one image dominates while the other is suppressed, and dominance alternates periodically. Rivalry is useful for investigating perceptual selection and visual awareness. Here we describe several easy methods for creating and using binocular rivalry stimuli.

We describe a novel methodology for creating naturalistic 3-D objects and object categories with precisely defined feature variations. We use simulations of the biological processes of morphogenesis and phylogenesis to create novel, naturalistic virtual 3-D objects and object categories that can then be rendered as visual images or haptic objects.

Mice can swim, but many strains appear to find this activity stressful. To overcome this problem mazes have been devised where escape from shallow water is used to motivate behaviour. These have been demonstrated to support learning at least as good as the traditional and widely used Morris water maze.

Fagot & Paleressompoulle1 have published an automated learning device (ALDM) aimed at testing individual cognitive abilities in semi-free ranging monkeys. The main goal of our protocol is to use a network of ALDM test units to study social cognition in non-human primates.

We describe how to implement a battery of behavioral tasks to examine the processing and integration of sensory stimuli in children with ASD. The goal is to characterize individual differences in temporal processing of simple auditory and visual stimuli and relate these to higher order perceptual skills like speech perception.

Transferring a paradigm with a history of use in EEG experiments to an fMRI experiment is considered. It is demonstrated that manipulating the task demands in the visual oddball task resulted in different patterns of BOLD activation and illustrated how task design is crucial in fMRI experiments.

1Center for Innovative Care in Aging, Johns Hopkins University School of Nursing, 2Institute for Interdisciplinary Salivary Bioscience Research, Arizona State University, 3Johns Hopkins University School of Nursing, 4Johns Hopkins University Bloomberg School of Public Health

Disrupting reconsolidation is a promising approach to dampen the behavioral expression of fear memory in patients with anxiety disorders or posttraumatic stress disorder. In a series of human fear conditioning studies we showed that disrupting reconsolidation by the noradrenergic β-blocker propranolol is very effective in erasing conditioned fear responding.

The comparative species approach allows behavioral neuroscientists to explore various neurobiological factors associated with specific behaviors viewed as characteristic of a specific animal model. Taking advantage of naturally occurring differences in behavior between closely related species, this technique doesn’t require invasive techniques to manipulate the expression of the behavior.…

Attention control comprises enhancement of target signals and attenuation of distractor signals. We describe an approach to measure separately but concurrently, the neurophysiology of attending and ignoring in sustained intermodal attention, utilizing a passive control condition during which neither process is continuously engaged.

Human memory is limited. Throughout most of its history, experimental psychology has focused on investigating the discrete, quantitative limits of memory—how many individual pieces of information a person can remember. Recently, experimental psychologists have also become interested in more qualitative limits—how precisely is information stored?
The concept of memory precision can be both intuitive and elusive at once. It is intuitive, for example, to think a person can remember precisely how their mother sounds, making it possible to recognize one’s mother immediately over the phone or in a crowd. But how can one quantify the precision of such a memory? Exactly how similar is the memory to the voice itself?
To study the precision of memory and working memory, in particular, experimental psychologists have devised a paradigm known as delayed estimation. It has been used most often, thus far, to study the precision of visual memories, especially memory for color, and to understand how memory degrades the more one tries to remember at once. This video demonstrates standard procedures for investigating the precision of color working memory using delayed estim…

1Psychology Department, University of Illinois Urbana-Champaign, 2Neuroscience Program, University of Illinois Urbana-Champaign, 3Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign

The present work provides a comprehensive set of guidelines for manually tracing the medial temporal lobe (MTL) structures. This protocol can be applied to research involving structural and/or combined structural-functional magnetic resonance imaging (MRI) investigations of the MTL, in both healthy and clinical groups.

1Center for Molecular & Behavioral Neuroscience, Rutgers University, State University of New Jersey, Newark, 2Department of Audiology, University of the Pacific, 3Department of Otolaryngology, Head & Neck Surgery, Stanford University

High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain.

This protocol describes the complementary neuroimaging techniques of resting state structural connectivity, task-induced deactivation, and structural connectivity analyses to examine the default network in post-traumatic stress disorder. The use of synergistic methods could potentially lead to improved diagnostics and assessments of severity, outcome, and other relevant clinical factors.…

Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session.…

We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures.